For the vehicles in the current market, besides two traditional gear transmission systems of manual gear transmission and automatic gear transmission, there is also a popular “manual-automatic transmission” speed-changing system, which not only makes driver enjoy the driving fun of manual transmission, but also makes driver enjoy easy operation and convenience of automatic transmission.
In brief, the basic principle of the so-called “manual-automatic transmission” speed-changing system is arranging a set of automatic transmission apparatus into a general manual transmission gearbox. By this set of automatic gear transmission apparatus, the driver needs not to step down or release off the clutch pedal (in fact, there is no clutch pedal arranged), but only to poke the transmission rod or press the transmission button on the steering wheel to generate a transmission signal to the automatic gear transmission apparatus, which then controls the manual transmission gearbox to proceed gear up or gear down action to achieve a driving effect similar to that of manual transmission. Of course, if the driver is too lazy to decide a transmission position by himself, then the transmission position of the transmission rod can be positioned at the position of automatic transmission. In this situation, the automatic gear transmission apparatus will be taken over and controlled by the driving computer arranged in the vehicle. The driving computer will automatically decide the transmission timing according to the preset conditions, for example, vehicle speed, rotating speed of the engine, etc.
Since a manual transmission gearbox usually has several transmission forks and each of which is connected to different gear in the gearbox, when a transmission fork is pushed, the engagements of the gears in the gearbox are changed to achieve the objective of speed-changing transmission. In other words, the automatic gear transmission apparatus arranged with the manual transmission gearbox must be able to provide two kinds of action, i.e. “gear selection” (selecting the transmission fork) and “gear transmission” (pushing the selected transmission fork). In the traditional and conventional automatic gear transmission apparatus, two sets of independent power sources are usually adapted for driving these two actions of “gear selection” and “gear transmission,” respectively. For example, two sets of independent motors are adapted to actuate two sets of independent transmission mechanisms respectively to proceed “gear selection” and “gear transmission” sequentially, or an electromagnetic clutch is adapted for switching between “gear selection” and “gear transmission.” However, there are still many shortcomings in the conventional automatic gear transmission apparatus as stated in the following:
1. Higher cost of hardware. The conventional automatic gear transmission apparatus needs to use two sets of motors to sequentially proceed “gear selection” and “gear transmission,” so a relatively higher cost will be resulted from utilization of two sets of motors.
2. Higher consumption of energy. Under the operation state of the vehicle, the electromagnetic clutch is actuated frequently thus its energy consumption is relatively higher.
3. Higher cost of control. Some server and feedback driver must be adapted to achieve positioning control for “gear selection” and “gear transmission” actions, so its cost of controlling is relatively higher.
4. Larger limit of space. Since the conventional automatic gear transmission apparatus applies two sets of motors, the space occupied therein is relatively larger thus more restrictions on the position arrangement for each element are caused.
According to the above-mentioned drawbacks, the invention proposes an automatic gear transmission apparatus, capable of cooperating with a conventional manual transmission gearbox to provide an automatic gear transmission function, wherein only a single motor is used to proceed two kinds of action—“gear selection” and “gear transmission.”